Means for controlling the valve movement of gate-valves.



D. LIBBY, JR. MEANS FOR OONTROLLINGTHE VALVE MOVEMENT 0F GATE VALVES. 1 7 rrmouxon rrnnn'oow. 11, 1900.

963,230. Patented July 5, 1910.

To all whom it may concern:

Be it known that I, DORVILLE LIBBY, Jr., a citizen of the United States, residing in the city and county of San Francisco and State of California, have invented certain new and useful Improvements in Means for Controlling the Valve Movement of Gate- Yalves, of which the following is a specification.

The hereinafterdescribed invention relates to means for limiting or arresting the travel of the valve disk, at the limits of its movements'for opening and closing the valved outlets of a valve casing; t-he. object of the invention being to avoid the strains which tend to cause breakage and ofttimes does cause breakage of the casing body, more especially on the closing movement of the valve, and to provide against the bending of the valve stem and dislodgment of the emerges from the casing body, whether the valve be closed or opened, so that packing of the stem may be accomplished while the valve casing is filled with water under pressure.

7 In the drawings, wherein is illustrated a vertical sectional view of the valve casing 5, which collar and works on the screw-threaded section 6v and the working parts arranged therein, the numeral 1 is used to designate the valve casing proper, and 2 the outlets or water-ways leading therefrom. These outlets or waterways are controlled by the slidable valve 3, which, in the'present case, is a double disk valve. The said valve is held to a threaded valve stem 4, rotatably mounted within the valve casing, by means of a traveling collar is internally screw-threaded of the valve stem 4:. This traveling collar 5 is formed with shouldered extensions 7, which rest loosely within the grooved or circular seat 7 in the inner face of the valve 3, so that the valve is flexibly held to the traveling collar 5. Thescrew-threaded portion of the valve stem 4 is situated within the pressure chamber 8 of the valve casing, the u per end portion of the rotatable stern extenglng through the contracted portion 9 of the valve casing and into the hood or bonnet 10 secured thereto and which is closed by the removable cap or cover 11, bolted thereto. This hood lO constitutes the upper I Specification of Letters Patent. Application filed October 11, 1909. Serial No. 522,043.

operated by a Patented July 5, mic.

or head section of the valve casing and w thin the same is situated the drivemeans for operating tion thereto. In the present case, the drive means consists of a gear 12 on the'valve stem meshing with drive nut 14, held 1n locked engagement therewith.

Within the upper portion of the valve casing is formed an enlarged seat 15, on whic rests' the circular flange 15 of a gland 16, through which extends the lower unthreaded portion of the valve stem/1, and on the circular flange of which bears the thrust collar 16" of the valve stem, which in turn is held .to its seat.by the upper gland 17, secured'in place by the inner Wall portion 18 of the valve casing section 10 bearing thereon. 'A water tight joint is thus formed between the valve stem 4 and the pressure chamber 8 of the valve casing, which permits the cap or cover 11 of the hood or head section 10 being uncovered for permitting of repair of the drive mechanism and packing of. the working parts located therein without water leakage taking place,

. which is a feature of importance where the chamber 8 is filled with water under pressure.

The traveling collar 5 is held onto the valve'stem 4:, or rather prevented from unscrewing therefrom, by means of a lock nut 19, screwed ontothe lowerend of the valve stem, which nut serves as a limit stop for the downward travel of the collar 5, by reason of the innenshoulder portion 19. thereof impinging thereon when the collar reaches its lowermost position, which is the full downward-stroke of the valve 3. As rotation is imparted to the valve stem 4, the traveling collar 5 will screw onto or ofi' of the screw threaded portion of the said stem, depending on the direction of rotation 1mparted thereto. On a rotatlon of the valve stem -to open or unseat the valve 3, the traveling collar will move upwardly on the valve" stem, until its upward movement is arrested by the upper end of the collar bearing against the lowerend'of the gland 16, when the collar 1s brought to a state ofrest. On an opposite rotation being given to the valve stem, the traveling collar will descend untll the shouldered portion 19 bears onto the lock nut 19,

a pinion 13, which pinion is' carrying'the valve 3 therewith,-

which time the valve 3 will be fully seated and further downward movement of the traveling collar arrested. By this means the downward stroke or movement of the traveling collar is positively arrested on the valve being fully seated, hence danger of the valve casing being excess of pressure being applied to the valve after having seated itself 1s avoided, which permits of the valve casing being constructed of lighter material than heretofore, where suflicient metal had to be incorporated therein to resist such excessive strains. Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is In a gate valve, the combination with the valve casin provided with a pressure chamber, a hoo section united to the casing and forming a chamber for the drive means, connection between said means and a rotabroken by an table non-vertically movable stem extended through the pressure chamber and into the hood section, a water tight joint between the pressure chamber of the casing and the chamber of the hood, a slide valve for con trolling the water-ways of the valve casing, a traveling collar movable on the screwthreaded portion of the valve stem within the pressure chamber, a flexible connection between said collar and the slide valve, and means within the valve casing and on the valve stem for arresting the movement of the traveling collar on the same reaching the limit of its stroke in either direction.

In-testimony whereof I. have signed my name to this specification in the presence of two subscribin witnesses.

ORVILLE LIBBY, JR. Witnesses: w

N. A. AOKER, D. B. RICHARDS. 

